#include <iostream>
using std::cout;
using std::endl;

namespace wd
{
int num = 200;

void display(){
    cout << "display()" << num << endl;
}
//不能在此进行访问
/* display(); */
/* num; */
}

namespace wd
{
//int num = 300;//error
int num2 = 300;
}


void test0(){
    cout << wd::num << endl;
    cout << wd::num2 << endl;
    wd::display();
}

int main(void){
    test0();
    return 0;
}
